Chrysler LLC reportedly is initiating a new round of layoffs, with plans to cut 1,000 salaried workers worldwide by Sept. 30.

The move marks the fourth time in 18 months the auto maker has undertaken significant staff reductions.

Employees learned of the workforce cuts in a company memo today, which says there will be a reduction in contract workers, as well, although no specifics are given.

Nancy Rae, executive vice president for human resources, says in the memo the “incremental reduction…is unfortunately necessary” due to “the continued deterioration in the U.S. automotive market.”

The Auburn Hills, MI, auto maker employs about 18,500 white-collar workers and 2,700 third-party contractors, The Detroit News says.

Chrysler reportedly will achieve its target through a combination of retirements, buyouts and attrition, although involuntary separation may be necessary, according to the memo.

The packages being offered are similar to previous plans.